ILC-BAW1 Interim Summary and Further Plan Akira Yamamoto, Marc Ross and Nick Walker GDE Project...

BAW1-2, Technical Address 1

ILC-BAW1Interim Summary and Further Plan

Akira Yamamoto, Marc Ross and Nick Walker

GDE Project Managers

Reported at BAW1, held at KEK, Sept. 9, 2010

10-9-9, A. Yamamoto


The 1st BAW Announcement http://ilcagenda.linearcollider.org/conferenceDisplay.py?confId=4593

10-9-9, A. Yamamoto

10-9-9, A. Yamamoto BAW1-2, Technical Address 3

SB2009 Themes

N Walker


Updated ILC R&D / Design Plan

Major TDP Goals:• ILC design evolved for

cost / performance optimization

• Complete crucial demonstration and risk-mitigating R&D

• Updated VALUE estimate and schedule

• Project Implementation Plan

Release 5Aug. 2010


Baseline Assessment Workshops• Face to face meetings• Open to all stakeholders• Plenary

TLCC Process

• Open plenary meeting• Two-days per theme• Two themes per workshop

– Two four-day workshops

• Participation (mandatory)– PM (chair)– ADI team / TAG leaders

• Agenda organised by relevant TAG leaders– Physics & Detector Representatives– External experts

• Achieve primary TLCC goals– In an open discussion environment

• Prepare recommendation

5


Baseline Assessment WorkShops

When Where What

WAB 1 Sept. 7-10, 2010

KEK 1. Accelerating Gradient2. Single Tunnel (HLRF)

WAB 2 Jan 18-21, 2011

SLAC 3. Reduced RF power4. e+ source location

Baseline Assessment Workshops• Face to face meetings• Open to all stakeholders• Plenary


Time-Table / Agenda (Sept. 7)updated: August 27

Day Am/pm Subject Chair/presenter

9/7 Single Tunnel ML Design and HLRF -1 S. Fukuda / C. Nantista

9:0 0 90 min

Opening and Introduction- Opening address- Report from AAP- BAW1 objectives and goals

Chair: S. Yamaguchi- A. Suzuki (KEK-DG)- E. Elsen- A. Yamamoto (GDE-PM)

10:45 90 min

Single tunnel CF design and HLRF design- Single tunnel CF design status (1 hour)- General HLRF design in SB2009 (30 min)

Chair: T. Shidara- A. Enomoto - S. Fukuda

13:30120 min

HLRF KCS-KCS design and R&D status (45 min)-Demonstration of feasibility (45 min)

Chair: S. Fukuda- C. Nantista - C. Adolphsen

15:45105 min

HLRF – EU XFEL and RDR - Introduction (20 min)- Experience from XFEL (1 hour)- RDR configuration (as backup) (10 min)- Discussion (15 min)

Chair: N. Walker-M. Ross -W. Bialowons - S. Fukuda - ALL

10-9-9, A. Yamamoto


Time-Table / Agenda (Sept. 8)Day Am/pm Subject Convener/presenter

9/8 Single Tunnel ML Design and HLRF -2 S. Fukuda / C. Nantista

9:00 DRFS -DRFS design and R&D status-Installation strategy-(1 hour total)

Chair: C. Nantista- S. Fukuda - S. Fukuda

10:45 HLRF and LLRF-LLRF requirements/issues for KCS 30-LLRF requirements/issues for DRFS 30-Requirements from Beam Dynamics 30

Chair: T. Shidara- C. Adolphsen - S. Michizono - K. Kubo

13:30 Operational consideration- Sorting cavities in relation with HLRF 30- Gradient and RF Power Overhead 30

Chair: C. Adolphsen- S. Noguchi- J. Cawardine

15:45 Discussions and Recommendations- General discussions and questions- Summary and recommendations

Chair: A. Yamamoto- TBD- ALL

10-9-9, A. Yamamoto


Single Tunnel Proposal: intro 1

• The proposal to go to a single tunnel solution for the Main Linac technical systems remains essential that outlined in the SB2009 report.

• The primary motivation was and remains a reduction in project cost due to the removal of the service tunnel for the Main Linac.

• The original proposal was based on the adoption of two novel schemes for the HLRF:– KCS– DRFS

• KCS has been identified as a preferred solutions for ‘flat land’ sites where surface access (buildings) is not restricted

• DRFS has been identified as being preferred solutions for mountainous region where surface access (buildings) is severely limited.

• Having both R&D programmes in parallel can be considered as risk-mitigation against one or other of them failiing.

• It is acknowledged that both these schemes require R&D– Programmes are detailed in the R&D Plan Release 5

• At the time of submission in December 2009, the two primary obstacles to adoption of a single tunnel were identified as

– Safety egress– Operations & Availability10-9-9, A. Yamamoto


Single Tunnel Proposal: intro 2• Both these issues were addressed during the 2009 and the

successful results reported in the SB2009 proposal.– The conclusions of these studies were later accepted by both AAP

and PAC• The remaining identified issues were with the technical

feasibility and cost of the HLRF solutions upon which the single-tunnel proposal was based.

• Two components to successful adoption were identified– Definition of acceptance criteria for TD Phase R&D for successful

demonstration of one or more of the novel proposed schemes– Inclusion in the designs of a risk-mitigation strategy, whereby a fall-

back to the RDR HLRF Technical Solution (in a single-tunnel) could be adopted, should the associated R&D not be considered successful.

• The remainder of these slides deals with these two additional points

10-9-9, A. Yamamoto


RDR HLRF Tech. Solution 1• Two scenarios have been cursorily studied for support of an RDR-like HLRF solution in a

single-tunnel1. 10MW MBK + (Marx) Modulator in the tunnel2. XFEL-like solution with modulators (low-voltage) accessible in cryo refrigeration

builds/caverns, with long pulsed cables feeding 10MW MBKs (via a pulse transformer) in the tunnel.

• Both are considered technically feasible.

• For 1, early investigations show the tunnel diameter would need to increase to 6.5m– This represents an estimated 10% increase in cost/unit tunnel length (~0.5% TPC)

considered acceptable.– Current availability* simulations (cf SB2009 proposal) suggest an additional ~5%

linac overhead (~2.5% TPC)• For 2:

– additional space for modulators in halls/caverns is required.– Cost of 3000 km of pulsed cable will be required.– Re-design of tunnel cross-section needed to accommodate cables.– Current availability* simulations (cf SB2009 proposal) suggest an additional ~2.5%

linac overhead (~1.3% TPC)

* see later comments on availability10-9-9, A. Yamamoto


RDR HLRF Tech. Solution 2• It is proposed that these RDR-like single-tunnel

solutions be carried forward in parallel, to enough detail to support a cost estimate (incremental)

• This estimate – together with the scope of the necessary re-design work to adopt one of the scenarios, will be factored into the TDR Risk Assessment

• The main R&D and AD&I effort will continue to pursue the preferred baseline solutions for KCS and DRFS.

• In order to reduce the number of scenarios to be developed, we propose to phase out one of these RDR-like options within the next six-months

* see later comments on availability10-9-9, A. Yamamoto



9/9 Cavity: Gradient R&D and ML Cavity Gradient R. Geng/A. Yamamoto

9:00 Introduction and Current Status- Technical address for the 2nd part of WS - Overview from RDR to R&D Plan 5 - Progress of cavity gradient data-base/yield

Chair: M. Ross- A. Yamamoto- R. Geng - C. Ginsburg

10:45 R&D Status and further R&D specification- Fabrication, testing, & acceptance for XFEL/HG - R&D expected in cooperation w/ vendors - R&D w/ a pilot plant w/ vendor participation

Chair: K. Yokoya- E. Elsen- M. Champion - H. Hayano

13:30 Short-tem R&D and Specification- Field emission and R&D strategy- Gradient, Spread, Q0, Radiation: R&D specification, standardization

Chair: C. Pagani- H. Hayano - R. Geng

15:45 Long-term R&D ACD subjects and goals - Seamless/hydro-forming, Large Grain, Cavity shape variation, VEP, Thin Film, - Further R&D toward TEV/ML - Discussions for Cavity R&D and Recommendations

Chair: A. Yamamoto- R. Rongli to lead discussions

10-9-9, A. Yamamoto



9/10 ILC accelerator gradient and operational margin A. Yamamoto andJ. Kerby

9:00 Gradients from VTS to Operation- Introduction: Overview on ILC gradient specification at each testing / operation step - Terminology definition - Operational results from VT/HTS/CM tests in data base- Operational results from STF VT/CM tests at KEK

Chair: H. HayanoA. Yamamoto

M. Ross-C. Ginsburg - E. Kako

10:30 Operational margin- Lorentz Force Detuning and Effects on op. margin- Comments from LLRF and Beam Dynamics- Acceerator Operation gradient margin

Chair: N. Toge- E. Kako - (K. Kubo/C. Michizono) - N. Walker

13:30 Cost Impacts- Reminder on cost effects- List of systems / technical components affected by gradient specification change- A plan to prepare for communication w/ industries

Chair: N. Walker- P. Garbincius- J. Kerby

- A. Yamamoto

15:30 General Discussion and recommendation- General discussions- Summary and recommendations

Chair: A. Yamamoto- All

10-9-9, A. Yamamoto

Discussion Topics: Accelerating Gradient1st BAW, KEK, Sept. 9-10, 2010

• Gradient Improvement Studies: (Convener: Rongli Geng/A. Yamamoto) – Material/fabrication, surface processing, instrumentation and repair– Strategy to overcome ‘quench’, and ‘field emission’ and to maintain moderate cryogenic

load,– Strategy to define and specify ‘Emitted Radiation’, (Radiation that may result in

increased cryogenic-load and usable gradient limitations), – Improvement of gradient and achievement of adequate yield,

• Strategy for Accelerating Gradient in the ILC: (Convener: Akira Yamamoto) – Overview and scope of ‘production yield’ progress and expectations for TDP, including

acceptable spread of the gradient needed to achieve the specified average gradient,– Specifications of Gradient, Q0, and Emitted Radiation in vertical test, including the

spread and yield,– Specifications of Gradient, Cryogenic-load and Radiation, including the gradient spread

and operational margin with nominal controls, in cryomodule test,– Specifications of Gradient, Cryogenic-load and Radiation, including the gradient spread

and the operational margin with nominal controls in beam acceleration test,– Impact on other accelerator systems: CFS, HLRF, LLRF, Cryogenics, and overall costs.10-9-9, A. Yamamoto 15BAW1-2, Technical Address

Global Plan for SCRF R&D

Year 07 2008 2009 2010 2011 2012

Phase TDP-1 TDP-2

Cavity Gradient in v. testto reach 35 MV/m

ProcessYield 50%

ProductionYield 90%

Cavity-string to reach 31.5 MV/m, with one-cryomodule

Global effort for string assembly and test(DESY, FNAL, INFN, KEK)

System Test with beamacceleration

FLASH (DESY) , NML (FNAL) STF2 (KEK, extend beyond 2012)

Preparation for Industrialization

Production Technology R&D

10-9-9, A. Yamamoto 16BAW1-2, Technical Address


Cavity Gradient Yield as of June, 20102nd-pass cavity yield at >25 MV/m is (70 +- 9) %

improved to (74 +- 8) % >35 MV/m is (48 +- 10) %

improved to (56 +- 10) %LCWS2010

10-9-9, A. Yamamoto


Gradient Improvement PlanBased on Recent Understanding due to Globally Coordinated S0 Program

• Highest priority is to push yield up near 20 MV/m – the yield drop due to local (geometrical) defects near equator weld.

– Fab. QA/QC– Mechanical polish prior to heavy EP– Post-VT local targeted repair– Seamless cavity– Large-grain mat. From ingot slicing– Fine grain mat. Optimization

• Also high priority is to suppress field emission at high gradient (up to 42 MV/m) – and quantify its effect on cryogenic loss and dark current.

Eliminate Local defect(geo.) near equator weld

Remove local defect (comp.)and field emitter

10-9-9, A. Yamamoto


R&D Milestone in RDRrevised in Rel-5

Stage Subjects Milestones to be achieved Year

S0 9-cell cavity

35 MV/m, max., at Q0 ≥ 8E9, with a production yield of 50% in TDP1, and 90% in TDP2 1), 2)

2010/

2012

S1 Cavity-string 31.5 MV/m, in average, at Q0 ≥ 1E10, in one cryomodule, including a global effort 2010

S2Cryomodule-string

31.5 MV/m, in average, with full-beam loading and acceleration 2012

10-9-9, A. Yamamoto

ILC Accelerator, Operational Gradient

• Strategy for Average Accelerating Gradient in the ILC operation:– Overview and scope of 'production yield' progress and expectations for TDP,

• including acceptable spread of the gradient needed to achieve the specified average gradient,

– Cavity• Gradient, Q0, and Emitted Radiation in vertical test, including the spread and yield,

– Cryomodule• Gradient, Cryogenic-load and Radiation, including the gradient spread and

operational margin with nominal controls,– ILC Accelerator

• Gradient, Cryogenic-load and Radiation, including the gradient spread and the operational margin with nominal controls

– Strategy for tuning and control, • including feedback, control of ‘Lorentz force detuning’, tolerances and availability

margin,– Impact on other accelerator systems: CFS, HLRF, LLRF, Cryogenics, and overall costs.

10-9-9, A. Yamamoto 20BAW1-2, Technical Address


A possible balance inILC ML Accelerator Cavity Specification

10-9-9, A. Yamamoto

Single 9-cell cavity gradient

String Cavity gradient in cryomodule w/o

beam

String cryomodule gradient in accelerator

with beam35 MV/m, on average w/ spread above a threshold

33 MV/m, on average(or to be further

optimized)

31.5 MV/m, on average(or to be further

optimized)


ILC SCRF Cavity Specification and relationship to the R&D Programs

Cost-relevant design parameter(s) for TDR

Currently proposed specification

Relevant R&D programme

Comment

Mass production distribution (models)

S0 cost optimisation will require a model for the yield curves based on the S0 R&D results

Average gradient 35 MV/m S0 primary cost driver

Gradient spread ±20% (28-42 MV/m) S0/S1/S2 cost-optimisation and performance balance

Average performance in a cryomodule (margin)

5%**

(33 MV/m average)

S1

total of 10% specified in RDR, but distribution not given (assumed equally split here)

Allowed operational gradient overhead for RF control (full beam-loading)

5%**

(31.5 MV/m average)

S2 (S1*)

Required RF power overhead for control

10% S2 (S1*)

10-9-9, A. Yamamoto

•Important input will also be gained from S1 program•** as a starting point for the discussions

BAW at KEK 2010.9.8, S.Noguchi 24

Quench GradientFeed-back Limit

Feed-back

Time

Gradient

Highest Gradient OperationFrom S. Nogichi

Operating Gradient

One Cavity – One Klystron

Best Configuration

Beam Timing


Higher Gradient Operation with Better Electric Power Efficiency Small Tuning Range & Less DLD Effect

Cavity Groupingwith Over-Coupling

10-9-9, A. Yamamoto


How should we do for Degraded Cavity ?

To Save other Good Cavities, We should have Tunability for RF Power & Coupling.

10-9-9, A. Yamamoto

Summary from S. Michizono

28BAW1-2, Technical Address

(1) LLRF overhead ~5%(2) Cavity gradient tilt (repetitive) ~5%(3) Pulse-to-pulse gradient fluctuation ~1%rms

RDR DRFS (PkQl) DRFS(Cavity grouping)

Operation gradient Max. 33 MV/m Average 31.5 MV/m Max. 38 MV/m

RF source 10 MW 800 kW

Waveguide loss 8% power 2% power 2% power

Static loss (Ql, Pk) 2% power 2% power 2% power

Kly Hv ripple 2.5% power 2.5% power 2.5% power

Microphonics 2% power 2% power 2% power

Reflection 0% power 14% power 0% power

Other LLRF margin 10% power 10% power 5%~10% power

Ql tolerance 3% (2) 3% (2)

Pk tolerance 0.2dB (2) 0.2dB (2)

Detuning tolerance 15Hz rms(3) 20Hz rms (3)

Beam current offset 2% rms (3)

RF p

ower

Tole

ranc

e

We have to examine these numbers experimentally. Tolerance should be discussed with cavity and HLRF group. If the tolerance is smaller, better gradient tilt would be possible.10-9-9, A. Yamamoto

Quench limits and operating gradients for 1.3GeV (FLASH ACC4-7)from J. Carwardine

20.9 MV/m 23.7 MV/m 24.8 MV/m 27.5 MV/m

Avg Emax:31.4 MV/m

Avg Emax:28.6 MV/m

Avg Emax:27.9 MV/m

Avg Emax:23 MV/m

ACC67ACC45

29BAW1-2, Technical Address10-9-9, A. Yamamoto

Ideally, all cavities reach their respective quench limits at the same forward power

25.7 MV/m 28.5 MV/m

4.6 MW klystron power (est.) 5.5 MW klystron power (est.)

23.0 MV/m 26.1 MV/m

ACC6 C2 will quench first (artifact of RF distribution

forward power ratios)

Reality: errors in power ratios due to manufacturing tolerances of rf attenuators(In this case: tolerances are of the order +/-0.1dB)

Avg Emax:31.4 MV/m

Avg Emax:28.6 MV/m

Avg Emax:27.9 MV/m

Avg Emax:23 MV/m

30BAW1-2, Technical Address10-9-9, A. Yamamoto


Subjects to be further studied in TDP-2

• Further Studied in TDP-2– How wide cavity gradient spread may be

acceptable in balance of HLRF power source capacity and efficiency?

– How large operational margin required and adequate in cryomodule and accelerator operation?

10-9-9, A. Yamamoto

BAW1-2, Technical Address

Discussionstoward consensus/recommendation

• Observation– Challenging operational margin in accelerator operation to be reliable enough

for sufficient availability for physics run.

• Our Strategy Proposed– Make our best effort with forward looking position to realize the accelerator

operational gradient to be 31.5 MV/m, as proposed in RDR, (and) on average with reasonable gradient spread,

– Keep cost containment concept resulting in the ML tunnel length fixed and not to expand,

– Prepare for the industrialization including cost and quality control.

– Ask physics/detector groups to share our observation and forward looking strategy

10-9-9, A. Yamamoto 32


Summary - 1BAW1 Objectives and Goals

• Assess technical proposal in SB2009• Confirm R&D Plan required and Goal in TDP-2• Discuss Impact across system interfaces, cost,

and schedule, • Discuss toward consensus in GDE and

Physics/Detector groups to prepare for TLCC.

10-9-9, A. Yamamoto


Summary – 2Tasks in each day/session

Date Main Theme Tasks

Sept. 7 IntroductionKCS: Design and R&DRDR: Technical

Make the workshop tasks clearProcess for the reality including costFeasibility as a backup solution

Sept. 8 DRFS: Design and R&DLLRF/ControlDiscussions

Process for the reality including costR&F operation margin for cavity/acceleratorRecommendation

Sept. 9 Cavity Gradient R&DDiscussions

Strategy for cavity gradient improvementShort-term and long-term strategy to be clear

Sept. 10 ML Accelerator GradienDiscussions

Accelerator gradient including spreadAppropriate balance of gradient in cavity/cryomodule/ML-accelerator, Adequate/required/acceptable gradient margin in accelerator operationRecommendation

10-9-9, A. Yamamoto

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